In the United States of America, wireless carriers typically do not charge wireline carriers a per-minute charge for carrying their calls. Instead, wireless carriers in the United States typically charge the wireless subscribers for both incoming and outgoing calls. Outside of the United States, however, wireless carriers typically impose per-minute charges for terminating calls to wireless telephone numbers. Those charges may be referred to as wireless termination charges, and the practice of imposing wireless termination charges may be referred to as wireless carrier access billing (CAB).
Currently, carriers of international calls are unable to determine, in advance of customer billing, whether an international call has been terminated to a wireless or wireline number, and if wireless, which carrier. Consequently, international carriers are unable to bill customers appropriately, and international carriers are estimated to be losing approximately one billion dollars per year in revenue as a result of these inabilities. They are also unable to route calls directly to the correct wireless carrier, increasing their transport expenses.